July 25, 2013

Precommitment A More Effective Self-Control Strategy Than Willpower

The key to losing weight, or saving for the future, is avoiding temptation all together, according to a new study from the Universities of Cambridge and Dusseldorf. The study on self-control suggests avoidance is a better strategy than depending on will power alone.

The study, published in Neuron, compared the effectiveness of willpower versus voluntarily restricting access to temptations, called 'precommitment'. For example, precommitments can include avoiding purchasing unhealthy food and putting money in savings accounts with hefty withdrawal fees. The team also examined the underlying mechanisms in the brain that play a role in precommitment in order to understand why this strategy is so effective.

"Our research suggests that the most effective way to beat temptations is to avoid facing them in the first place," said Molly Crockett, who undertook the research while at the University of Cambridge and is currently a Sir Henry Wellcome Postdoctoral Fellow at UCL.

The study participants were healthy male volunteers. The researchers gave the men a series of choices where the men had to decide between a tempting "small reward" available immediately, or a "large reward" available after a delay. The small rewards were mildly enjoyable erotic images. The large rewards were extremely enjoyable erotic pictures. Such pictures are immediately rewarding at the time of viewing, allowing the researchers to probe the mechanisms of self-control as they unfolded in real-time. The pictures were chosen instead of rewards like money, which could only provide a reward after the subjects had left the laboratory.

The small reward was continuously available during some of the choices, making it necessary for the subjects to exert willpower to resist choosing it until the large reward became available. For other choices, however, the participants were given the opportunity to precommit. Before the tempting option became available, the subject had the ability to prevent themselves from ever encountering the temptation.

Participants' choices and brain activity were measured as they made these decisions. The researchers found precommitment was a more effective self-control strategy than willpower. The participants were more likely to get the large reward when they had the opportunity to precommit. The team found those with the weakest willpower, the most impulsive of the subjects, benefited the most from precommitment.

The study allows the team to identify the regions of the brain that play a role in willpower and precommitment, finding that precommitment specifically activates the frontopolar cortex, a region involved in thinking about the future. When the frontopolar cortex is engaged during precommitment, the team found it increases communication with the dorsolateral prefrontal cortex, a region of the brain that plays an important role in willpower. Identifying the brain networks responsible in willpower and precommitment opens new avenues for understanding failures of self-control.

"The brain data is exciting because it hints at a mechanism for how precommitment works: thinking about the future may engage frontopolar regions, which by virtue of their connections with the dorsolateral prefrontal cortex are able to guide behavior toward precommitment," said Tobias Kalenscher, from the University of Dusseldorf.